6. Choosing a Computer
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6. Choosing a Computer 6. Choosing a Computer Presentation Transcript

  • B.A. (Mahayana Studies) 000-209 Introduction to Computer Science November 2005 - March 2006 6. Choosing a Computer
    • Considering the hardware choices involved in choosing a computer.
  • Overview
    • 1. How to Choose a Computer
    • 2. The Processor
    • 3. The Hard Disk
    • 4. External Data Storage
    • 5. Keyboard / Mouse
    • 6. The Monitor
    • 7. The Sound Card
    • 8. Room for Expansion
    • 9. Laptop Battery Life
    • 10. The Printer
    • 11. A Computer's Life
    • 12. The Software
    • Decide how much to spend, and stick to it.
    • How will you use the computer?
      • what software will you need?
    • Hardware issues
      • desktop or laptop?
      • processor, hard disk external storage, keyboard, mouse, monitor, sound card, printers, etc.
      • when to buy?
    1. How to Choose a Computer
  • Windows XP
    • Minimum hardware for Windows XP:
      • Pentium 500 MHz processor, or higher
      • 256 MB of RAM or more
        • more memory is the best way to improve XP's speed
      • 4 GB hard drive (1.5 GB for XP)
      • a Super VGA monitor with (800x600) resolution
        • try 1024x768 or higher with 24-bit colour
      • CD-ROM or DVD-drive
      • keyboard and mouse
      • sound card and speakers
  • 1.1. Lotus, July 2005 Free Items: printer, ink, table, chair, fax modem, 50 hours on Internet, speakers, cover, mouse pad, adapter, microphone, 10 CD disks, monitor frame and 3 others cover, mouse pad, adapter, microphone, speakers
  • Some Buzzwords
    • DDR: Double Data Rate SDRAM; faster RAM
    • HDD: Hard Disk Drive
    • FDD: Floppy Disk Drive
    • CD-RW 52-32-52:
      • the CD drive can write data at 52x speed, it can rewrite data at 32x speed, and it can read data at 52x speed
    • USB: Universal Serial Bus
      • a plug-and-play interface between a PC and devices such as hard drives, audio players, scanners, and printers
    continued Others Later
    • AGP: Accelerated Graphics Port; speeds up 3D
      • many companies sell AGP-compatible graphics cards
    • 10/100 LAN: Local Area Network
      • dual speed 10/100 Mbps (bits/sec) with auto-sensing
    • HT: hyper threading; multiple threads of execution
    • VIA: VIA Technologies, Taiwan; makes motherboards
    • FSB: Front Side Bus; links motherboard to the CPU
    • Chip makers assign model numbers or names to processors.
      • the chip model indicates the processor’s architecture
    • Each new model is faster, with other enhancements.
    2. The Processor
    • Pentium 4 with hyper-threading
      • 3.00 to 3.80 GHz
      • model numbers include 670, 660, 650, 640, 630 571, 570J, 561, 560J, 560, 551, 550J, 550, 541, 540J, 540, 531, 530J, 530, 521, 520J, 520
    • Celeron
      • can do the same operations as the Pentium
      • less expensive, but slower
      • 950 MHz to 2.80 GHz
    Intel Chips
  • Intel Chip History
    • 1982: Intel 286
      • 134,000 transistors, 12.5 MHz clock speed
    • 1985: Intel 386
      • 275,000 transistors, 33 MHz
    • 1989: Intel 486
      • 1.2 million transistors, 50 MHz
    • 1995: Pentium Pro
      • 5.5 million transistors, 200 MHz
    • 1999: Pentium 3
      • 28 million transistors, 733 MHz
    • 2000: Pentium 4
      • 42 million transistors, 1.5 GHz (1500 MHz)
  • Part of Intel's Range in 2005
    • Desktop
        • PentiumExtreme Edition, Pentium D, Pentium 4 supporting Hyper-Threading, Pentium 4, Celeron D, Celeron
    • Notebook
        • Pentium M, Mobile Pentium 4 supporting Hyper-Threading, Mobile Pentium 4, Mobile Pentium 4 Processor-M, Celeron M, Mobile Celeron Processor
    • Clock speed
      • indicates how many instructions can be processed per second
    • Level 1 cache - cache built into the processor
    • Level 2 cache - the cache is on a separate chip
      • faster than level 1 cache
    • Benchmark tests
      • a set of standard processing tasks that measure the performance of hardware or software
    Factors Affecting Price
  • Processor Overall Performance : July 2005 from http://www.cpuscorecard.com/
    • The 'best' amount of RAM depends on the OS and applications you plan to use.
      • at least 64 - 256 MB to run Windows XP
      • 256 MB or more is better
      • a very good way of improving performance
    2.1. How much RAM?
    • Storage capacity is measured in gigabytes (GB).
      • get at least 40 GB
    • Hard disk speed is usually measured in revolutions per minute (RPM)
      • the higher the RPM , the less time you'll spend waiting for your computer to access files
      • best for desktops: 5400, 7200 RPM
      • best for laptops: 4200, 5400 RPM
    3. The Hard Disk
    • Disk drives are classified by their type of controller
      • the hardware that rotates the hard disk, and moves the read-write head
    • Popular drive controllers are:
      • Ultra ATA , EIDE, SCSI
      • Ultra ATA is twice as fast as EIDE
      • SCSI is slightly faster than EIDE
    Hard Drive Controllers
    • Floppy disk drives are on their way out.
    • Rewritable CDs (CD-RW) are popular.
      • increasingly with DVD support
    • Many computers include USB ports for flash drives
      • get a USB port supporting version 2.0 (potentially 40x faster than 1.1)
    4. External Data Storage
  • Flash Drive
    • Uses flash memory
      • a rewritable memory chip that remembers its content without needing a power supply ( non-volatile )
    • A flash drive can be added/removed from the PC while the macine is switched on ( hot-swappable ).
    • Storage capacities: 64 - 256 MB
  • 5. Keyboard/ Mouse Microsoft’s Natural Keyboard may help prevent computer related injuries. Wireless
  • Mouse Types
    • Mechanical, optical, laser mice
    • Cord or cordless?
    • How many buttons?
    • Mouse wheel?
    • Connector type
      • serial port, USB port
  • Laptop Input Choices Track point Trackball Touchpad
    • CRT (cathode ray tube) monitors use similar technology to television sets
      • inexpensive and dependable
    • LCD (liquid crystal display) monitors produce images by manipulating light within a layer of liquid crystal cells.
      • compact, lightweight, easy to read
      • standard on laptops
      • flat-panel displays are available for desktops
    6. The Monitor
    • Advantages of LCD
      • display clarity
      • low radiation emission
      • portable
      • compact
    • 3x the price of a CRT
    Flat Panel Displays
    • Screen size is the measurement in inches from one corner of the screen diagonally across to the opposite corner.
    • The viewable image size (vis) excludes the screen's black border from the calculation.
    Monitor Sizes A monitor’s viewable image size is less than the screen size.
    • Dot pitch - a measure of image clarity
      • smaller dot pitch means a crisper image
    • Maximum resolution : the maximum number of pixels a monitor can display
      • a typical max. resolution is 1280 x 1024 pixels
    Monitor Resolution
    • Often the graphics card may be a part of the motherboard
      • especially in laptops
      • the card should have 8 - 64 MB of video memory
    • The most powerful graphics cards are used for 3D graphics
      • sometimes called GPUs (graphics processing units)
    Graphics Cards continued
    • The main 3D graphics card manufacturers are:
      • ATI Technologies
        • cards: Radeon 7/8/9000 Series, Radeon X Series
      • NVIDIA Corporation
        • cards: GeForce including GeForce FX Series, GeForce 6 Series, GeForce 7 Series
  • SVGA Graphics Cards
    • Super Video Graphics Array (Super VGA or SVGA) is the most popular display type.
    • SVGA graphics cards have a standard resolution of 800x600 (480,000 pixels).
    • They should be able to offer resolutions up to 1280x1024, with 24-bit colour (16 million colours).
    • Passive matrix screen - relies on timing to make sure the liquid crystal cells are illuminated.
    • Active matrix screen - updates rapidly
      • essential for crisp display of animation, video
      • found on newer laptops
    Laptop Display Screens
    • A sound cards i mproves a computer's sound quality, and adds other sound capabilities:
      • makes it possible to use speakers, a stereo, and a microphone to record and play sound
      • some sound cards also include MIDI
    • Some sound card manufacturers
      • Turtle Beach, Diamond, Creative Labs
    7. Sound Cards
  • MIDI
    • Musical Instrument Digital Interface
    • MIDI enables electronic instruments, such as synthesizers, samplers, sequencers, and drum machines, to communicate with one another and with computers.
    • When you buy a computer, make sure it has expansion options.
    • Motherboard expansion slots to add peripheral drivers.
    • Internal bays : mounting brackets in the computer case for devices.
    8. Room for Expansion continued
    • External bays : openings in the case so that devices can be (temporarily) connected to the computer.
    • PCMCIA expansion slots are found in many laptops. Classified according to size:
      • Type 1 - thinnest, for memory expansion
      • Type 2 - for modems, sound cards, network cards (most common)
      • Type 3 - thickest, for hard disk drives
    • Make sure the laptop has plenty of USB ports (2-6).
    Laptop Expansion
    • The length of time a laptop's battery will last depends on:
      • the processor speed
      • the screen type (e.g. active matrix LCD)
      • how many peripherals are attached
    • Hot swap : the ability to swap batteries while the computer is on.
    9. Laptop Battery Life
    • Details to consider when choosing a printer:
    • Resolution
      • printer resolution is measured in dpi (dots per inch), the number of dots it can print per linear inch
      • more dpi means the final image will be clearer
    • Colour capability
      • can the printer support colour?
    10. The Printer continued
    • Print speed
      • print speed is measured by pages per minute (ppm) or characters per second (cps)
      • colour printing takes longer than black and white
      • text prints faster than graphics
      • ten pages per minute is a typical speed
      • duty cycle : the number of pages that can be printed per month
    • Printer cost
      • from $100 to $5000
    • Per-copy cost
      • these are the ongoing costs for the printer, including ribbons, ink cartridges, and toner
      • the cost estimate assumes that a page uses an average amount of text, graphics, and colour
    • Warranty
      • how long does the warranty last for?
      • does it cover all printer parts?
    • The most popular type of printer
      • it produces low-cost colour and black-and-white printouts
    Inkjet Printers Black ink cartridge Colour ink cartridge continued
    • The print head uses a series of nozzles that spray coloured inks onto the paper
    • The laser in the printer charges an electrostatically sensitive drum to accept toner which is then fused to the paper.
    Laser Printers
  • Features
    • Higher quality output than inkjets
    • More expensive to buy than inkjets
    • Less expensive to operate than inkjet
    • The toner cartridge and drum cost approx. $70
    • Dot matrix printers prints by striking groups of wires or thin rods onto an ink-coated ribbon against paper.
    Dot-matrix Printers?
  • Features
    • Old/reliable technology: introduced in the 1970s
    • Low quality output
    • Can print onto multipart carbon forms
    • Used for “back-office” applications that need low operating cost and dependability.
    • A $4 ribbon can print 3 million characters
    • The lifecycle of a computer has five phases:
      • product development
      • product announcement
      • introduction
      • maintenance
      • retirement
    • Vaporware : computers (and software) that are announced but never produced.
    11. A Computer's Life
    • Toshiba Satellite
      • Pentium M, 1.50GHz, 256MB RAM
      • 60 GB Hard Disk
      • CD RW / DVD
      • modem
      • 15.4 inch active matrix display
    Price Drops over Time high price low price average price Weeks up to July 2005
  • Computer Companies
    • Top-tier companies
      • computer business for many years
      • Apple, Compaq, IBM
      • more expensive computers
      • responsible for many innovations
    • Second-tier companies
      • newer companies
      • Gateway, Packard Bell, Dell
      • less expensive computers, same quality
      • limited research and development
    • Third-tier companies
      • smaller startup companies
      • sell locally
      • less expensive
      • may use poorer quality components
      • more likely to go out of business
      • technical support depends on the owner
    • Build your own
      • readily available parts
      • relatively easy assembly
      • customize to your own needs
    • Software publishers produce software
    • Alpha test : first phase of testing done in-house
    • Beta test : conducted by off-site tester
    12. The Software
    • The original version (release) of software is typically version 1.0
      • a new version is indicated by a new number (e.g. 2.0)
      • a new version is usually a major improvement
    • Revision : a release that fix bugs or makes small changes
      • the revision number is separated from the version number with a period (e.g. 1.1)
    Software Versioning
    • Street price : average discounted price
    • Version upgrade price : discounted price for owners of an earlier version of the software
      • must show proof to the vendor
    • Competitive upgrade : special price for switching to a competitor’s product
    • Upgrading software is important
      • less technical support for older versions
      • may lose eligibility for special pricing
    Software Pricing Issues
  • Other Software Issues
    • Compatibility with hardware/OS
    • Warranty
    • Technical Support
      • help-lines, local user groups, personal service
      • Web-based technical sites, newsgroups, mailing lists